Egyptian protesters shout anti-government slogans and display bread to symbolize the high number of people living in poverty during a protest in Tahrir Square in Cairo on Friday.

CAIRO — Egyptian security forces fired salvos of tear gas at rock-throwing protesters in several northern cities on Friday, as thousands marched in protest against the rule of Islamist President Mohammed Morsi and his fundamentalist Muslim Brotherhood group.

The street protests came in defiance to hardline Muslim clerics who issued religious edicts this week calling for the killing of opposition leaders.

Carrying Egyptian flags and pictures of slain protesters, demonstrators took to the streets in Cairo, Alexandria, the restive Suez Canal city of Port Said and several Nile Delta cities where the Brotherhood’s popularity has been sharply eroding.

“Down with the rule of the Guide,” the crowds chanted, referring not to Morsi but to the top leader of the Brotherhood, Mohammed Badie, who critics say is calling the shots for the president from behind the scenes.

In Cairo, protesters gathered at the central Tahrir Square and outside the presidential palace, where clashes turned violent last week and cameras filmed a protester stripped naked and beaten by security forces.

In Kafr el-Sheik, some 110 miles north of Cairo, riot police fired tear gas at protesters rallying in front of the office of governor Saad el-Husseini, who is a member of the Muslim Brotherhood.

In Alexandria, protesters tore down a Brotherhood sign and burned it in front of the group’s office while security forces used tear gas to disperse protesters in front of the governor’s office. Similarly, in Tanta, also north of Cairo, security forces fired tear gas canisters in clashes with rock-throwing protesters.

Egypt has witnessed a fresh cycle of violence over the past two weeks since the second anniversary of the 2011 uprising that deposed longtime autocrat Hosni Mubarak. Clashes across the country have left scores dead and hundreds injured. Incidents of abduction, torture and the killings of activists have raised concerns of excessive use of force by police, which was one of the main drivers of the 2011 revolt.

Egypt’s opposition is demanding Morsi form a new coalition government, open an investigation into the killings of protesters over the past months and give guarantees that upcoming parliamentary elections will be fair and free. They also want him to form a commission to amend the country’s newly adopted constitution, which was drafted by an Islamist-led panel and approved last December in a rushed referendum in which only 32 percent of eligible voters took part.

Morsi and his allies accuse the opposition of trying to incite street violence to seize power after failing at the ballot box.

In a statement on Friday, Murad Ali, a spokesman for the Freedom and Justice party — the Muslim Brotherhood’s political arm — warned the opposition that it would be responsible for any acts of violence that occur during protests. He also called them “losers.”

The Friday protests come amid substantial public anxiety after hardline Muslim clerics issued religious edicts, known as fatwas, calling for the killing of Morsi’s political opponents, and while Tunisia is witnessing a new wave of unrest after an anti-Islamist opposition leader was gunned down.

Tunisia is the birthplace of the region’s so-called Arab Spring uprisings in 2011 that brought an end to three decades of rule by Egypt’s Mubarak, eventually leading to Morsi’s election last summer.

The opposition says it will continue protests despite the fatwas, which the presidency and the government condemned as “terrorism.”

Hamdeen Sabahi, a leader of the opposition National Salvation Front, said in a message posted on his Twitter account: “We will continue our peaceful struggle with the Egyptian people and revolutionary youth to continue our revolution.”